Armature winding



c; F. JENKINS ARMATURE WINDING Filed July '7. 1932 INVENTOR Char/e5 FJenM/ns.

ATTORN EY July 4, 1933.

WITNESSE 4%.

Patented July 4, 1933 uNr-rE' srATes Fr es PATENT CHARLES F. JENKINS, .OF WILKINSBURG, PENNSYLVANIA, ASSIGNOR TO WE STm'G- HOUSE ELECTRIC & MANUFACTURING COMPANY, OF EAST PITTSBURGH, PENNSYL- VANIA, A CORPORATION OF PENNSYLVANIA i amvmrnnn WINDING Application filed July-7,

My invention relates to a special armature winding and a stepped-slot core therefor, and it has special relationto such windings and core, for, use in dynamo-electr c machines of unusually large current capacity at relatively small voltages.

The principal object of my inventlon is to provide an 'armature core having stepped slots, the top portion of which 1s approximately twice as wide and half as deep as the bottom portion, and to provide an armature winding, cooperating therewith, composed of portions of uniform cross-section throughout its length, said winding being arranged with two portions or'coil-sides disposed one above the other in the bottom portions of the stepped slots, and with two portions or coil-sides disposed side-by-side in portions of the stepped's'lots.

The same identical conductors which he in the top part of the slot, continue around and occupy the bottom part 'of another slot, thus providing a stepped-slotconstruction wlthout requiring the expedient of weld1ng'together two conductors of differently shaped cross sections.

The advantages structural fdetalls, and applications of my'invention are herelnafter. described and claimed and illustrated in the accompanying"drawing wherein Figure 1 is a front end view of a part of the top "a core of an armature embodying my invention, with 'theend connections of 'oneof the coils indicated in placey and with a: crosssectional view of the four 'OOIl :sldes or CD11 portions lying in place in some of the slots.

Fig. 2 is a top plan development showing the arrangemei-itoi theend-connections.

Fig. '3 is an end view of the development shown in Fig. 2,and

Fig. 4c is a front elevati'ona'l View of a few "of the commutator bars showing the'connectiOnof the windings to the commutator necks.

In designs in whlch =1-t 1s necessaryto place as much copper as possiblein the armature or rotor member of a dynamo-electric ma chine, a limitation has always been met, in the depth of slot which itis possible to. utillze, on account of the reduction in the width of readily perceived i A- ffurther effect of 1932. Serial no. 621,162.

the slots at the bottom ends relation in the tops of the as indicated at 18.

such construction will be when it is pointed out that, in an armatureof ten-inch diameter, I. have been able to use a depth of slot comparable to'an armature of eighteen-inch diameter,

by departing from the usual formof slot to 70 one in which the two bottom coil sides 16 are disposed in superposed relation, the slots being only large enough to accommodate the coil sides 16 and 18, with their insulating coverings 20.

the stepped-slot construction herein described is that it deepens the end windings 22 (Fig. 3'), and thence shortens the length of copper taken up by the end windings. This is brought about by the fact that the end windings are fd-isposed three-deep, as shown in Fig. '3, instead-of being disposed two-deep, as would have been the case if the bottom coil sides16 had been disposed in side-by-side relationinsteadoi i-nsuperposed relation as shown in Fig. 1.

The drawing shows to 'the armature member of a -kilowatt, lO-volt, direct-current generator. The coils are made from a rectangular copper strap,

each coil consisting of two lengths of strap which are connected in parallel. The coils are form-wound so that the bottom coil-sides 16 and the bottom front and rear end connections26 are disposed in superposed relationship, while the other ends of eachstrap,'after the strap is formed into a coil, will be insideby-side relationship, as indicated by coilsides f1'8:lying in the top sides of the slots and the upper end connections 28 at both the :com- 'inu tator end :an'd the rear endof the armature.

as indicated at 16, and lying y invention applied it is neceseach 6011 to be wound so as to be in efiect, of two coils connected in parallel, the coils being connected together by silver solder 32 and spot welds 33, as indicated in ldlg. 3.

I contemplate, however, that there w1ll be certain uses or applications of my invention V 1.-A dynamo-electric machine havinga and half as deep as in which the part of the coils shown in Fig. 2 may be separate coils or in parallel, the essential feature being that the coil sides under one of the field poles, at any mo ent shall be disposed in superposed relation, while the coil sides of the samepair of coils under the opposite field poles,-at the same moment, are disposed in side-by-side relation, whether the coils are connected in series or. parallel. In general, there may be any even number of coil-sides in each part of the slot, provided that there are twice as many coil-sides in side-by-side relation in the. top part of the slot as in the bottom part, and twice as many coil-sides in superposed relation in the bottom part of the slot as in the 'top part.

In accordance with my invention, I also provide a novel formv of connection of the armature coils to the necks 40 of my commutator bars 42, the commutator necksbeing furnishedwith stepped slots 44: for this purpose, with the distinction, however, top portions of the stepped-slots 44 each receivetwo armature-coil straps in side-by-side relation, whereas the bottom portions of these stepped-slots receive only one of the armature-coil straps, the-bottom strap of the pair being. cut off as indicated at 46 in Fig. 3, and.

being silver-soldered to the upper this point, as indicated at 32. 7

I claim as my invention:

strap at rotor member comprising a core having stepped slots, the top portion of the slots being approximately twice as wide and half as deep as the bottomportion,and an armature winding cooperating therewith, said armature winding being composed of portions of, uniform cross-section throughout its length, said winding being arrangedwith two portions disposed one above the other in the bottom portions of the stepped slots, and with two portions disposed side-by-side in the top portions of' the stepped slots.

2'. A low-voltage high-current armature for a dynamo-electric. machine, comprising a c'ore'having stepped slots, the top portion of the slots being approximately twice as wide the bottomportion, and an armature winding cooperating therewith,

said armature winding being composed of a V 7 they may be con,- nected in series with each other rather than that thethe top front and rear end-connections are in side-by-side relationship.

3. A low-voltage, high-current dynamoelectric machine comprising an armature core havingstepped slots, the top portion of the slots being approximately twice as wide and half as deep as the bottom portion, and an armature winding cooperating therewith, saidarmature winding being compose of a plurality of coils, each coil comprising two form-wound straps of substantially uniform cross-sectional shape and area throughout their lengths, said straps of each coil being mechanically and electrically joined together at a plurality of points and so formwound that the bottom coil-sides and the bottom front and rear end-connections are disposed in superposed relationship, the middle portions of the straps are in circumferentially displaced loops, and the top coilsides and the top front and rear end-connections are in'side-by-side relationship, and a commutator cylinder comprising a plurality of commutator bars having steppedslotstherein, the topportions of the. neck-slots twice as wide,

and of approximately the same depth,

as thebottom portions of theneckslots, the top front end-connections of the armature winding terminating in the top provided with necks being approximately portion's'of theneck-slots, and the top strap 7 of the bottom front end-connections of the armature winding terminating in the bottom portions of the neck-slots, the bottom straps of the bottom front end-connections terminating short of the commutator necks and being joined, near said termination to the respective superposed straps of the bottom front-end connections.

l; A dynamo-electric machine comprising an armaturewinding and a slotted armature core, characterized by the coil-sides of one pair of armature-winding coils being disposed in superposed relation in-the bottom portion of one slotand in, side-by-side relation in the top portion of a slot displaced substantially 180 electrical degrees from'the first-mentioned slot.

5'. An armature for a chine, comprising a core having stepped slots, the top portion of the slots being ap proximately twice as wide andhalf asdeep as the bottom portion, and an armature winding cooperating therewith, said armature dynamo-electric mawinding being composed of a plurality of coils made of form-wound lengths of strapconductors of substantially uniform crosssectional shape and area throughout their len ths, each strap-conductor being so formwound as to produce two coil-sides lying in slots, and two front and two rear end-connections, with an integral radial loop joining the two rear end-connections, there being two shapes of coils arranged in pairs, each pair being such that the bottom coilsides and the bottom front and rear end-connections are disposed in superposed relationship the middle portions of the straps are in circumferentially displaced loops, and the top coil-sides and the top front and rear end-connections are in side-by-side relationship.

6. A dynamo-electric machine armature comprising a'core having stepped slots,'the top portion of the slots being approximately twice as wide and half as deep as the bottom portion, and an armature winding cooperating therewith, said armature winding being composed of a plurality of coils each comprising one coil-side lying in the top portion of one slot and another coil-side lying in the bottom portion of another slot, characterized by an even number portion of each slot, there being twice as many coil-sides in side-by-side relation'in the top portion of each-slot as in the bottom portion of each slot, and twice as many coil-sides in superposed relation in the bottom portion of each slot as in the top portion of each slot.

In testimony whereof, I have hereunto subscribed my name this 16th day of June 1932.

CHARLES F. JENKINS.

of coil-sides lying in each 

